Devices which can be used to feed cuboidal objects, such as for example microchips, from a stock into a shaft, with the shaft having a rectangular or oval cross section, are known from document U.S. Pat. No. 4,960,195. U.S. Pat. No. 4,960,195 discloses a horizontal plate having orifices of identical size with a rectangular or oval cross section, the plate on its upper side exhibiting a depression around each orifice. At the level of the plate surface, the periphery of the depression exhibits an oval or rectangular form. The wall and the base of an oval depression are curved and the base of the oval depression narrows in the direction of the center of the orifice. Similar devices are known from JP 36630/1987 (cited in accordance with U.S. Pat. No. 4,960,195). In this case, the plate has a shaft with a rectangular cross section. On one side, the plate has a depression with a circular cross section, which narrows conically towards the center of the rectangular cross section.
The removal of balls from a supply in a specified quantity at a specified point in time and the positioning of the balls for the purpose of their controlled, mechanical removal is a more specific technical problem, for which a number of proposed solutions are likewise already described in the prior art.
U.S. Pat. No. 3,552,600 describes a ball dispenser, a device for controlling the removal of balls of identical size from a supply. The device disclosed therein comprises a supply container, a shaft with a hopper-shaped feed arrangement and a conveyor spindle. The latter contains a groove, by means of which a ball is removed from the shaft and ejected by causing the spindle to rotate.
U.S. Pat. No. 4,648,529 describes an arrangement having a ball reservoir that is connected to a circular hopper. The constricted end of the hopper faces towards the bottom and discharges into a channel, the diameter of which corresponds to the diameter of the balls in the reservoir. The balls, which are of identical size, arrive under the effect of gravity in the channel, in which they are arranged one after the other. At its end, the channel is interrupted by a lock chamber, which is able to accommodate only a single ball at a time. The lock chamber is movably arranged. The orifices in the lock chamber are slightly offset by means of an elastic spring, so that either a ball is able to leave the channel, but not the lock chamber, or so that a ball is able to leave the lock chamber, but not the channel. By pressing against the spring and subsequent relaxation, one ball at a time drops into the lock chamber and is then released from the device.
DE 198 18 417 C2 discloses a shaft to accommodate microbodies, for example balls, in conjunction with which the height of the shaft determines the number of microbodies that can be accommodated. The upper end of the shaft is expanded into the form of a hopper. The microbodies are removed individually from the shaft by means of a suction mechanism.
US 2002/0040521 A1 describes a template framework for positioning balls of solder. The template framework consists of a plate having chambers in the form of bores, in each of which a single ball of solder fits. The template framework is supported on a base in such a way that the orifices in the bores on the one hand face towards the base and on the other hand are open in an upward direction. Each bore is filled with a ball, so that the solder can then be fixed in the respective position on the base by heating by means of a laser. US 2002/0179696 A1 describes an arrangement for the positioning of balls of solder, in which a chamber of a template is filled from a superjacent ball supply, in conjunction with which there is arranged above the chamber a hopper-shaped groove, in which the balls from the supply collect and, for the purposes of charging, are led to the chamber.
EP 1 033 566 B1 discloses a device for filling a plurality of individual grinding spaces with balls, which are used as grinding balls. The device comprises a plate with 96 transcurrent, circular orifices, which are arranged in a regular form as an 8×12 grid pattern. The diameter of the orifices is larger than the diameter of the balls. Movably arranged on the plate is a slide, which, in the inserted state, constitutes the base of the orifices, so that in this state balls are capable of being inserted into the orifices. The plate is then moved over a block with grinding spaces, which are arranged in the same 8×12 grid pattern, so that the orifices in the plate are situated in alignment over the orifices in the grinding spaces. The slide is withdrawn from the plate, and the grinding bodies drop into the grinding spaces.
Balls, for example intended for use as grinding bodies, in many cases consist of materials which may not possess any smooth surfaces, but rather rough surfaces. Examples of this are balls made of glass or ceramic materials (for example sintered ceramics, hard porcelain), mineral rocks (for example marble, agate), metals (for example iron, tungsten carbide) or plastics (for example polyamide, Teflon) and two-phase bodies (for example steel bodies enclosed in Teflon).